1. Field of the Invention
The present invention relates generally to a magnetic disk drive, and more particularly to a negative pressure type magnetic head slider for a load/unload type magnetic disk drive.
2. Description of the Related Art
In recent magnetic disk drives with decreasing size and increasing storage capacity, it has been desired to reduce the flying height of a head slider and realize contact recording/reproduction such that the head slider flies a microscopic height from a recording medium such as a magnetic disk or comes into contact with the recording medium. To reduce the flying height of the head slider, the surface roughness of the surface of the magnetic disk must be reduced. In a contact start and stop (CSS) type magnetic disk drive heretofore widely used, a flying surface of a magnetic head slider comes into contact with a magnetic disk upon stoppage of rotation of the magnetic disk, and flies above the surface of the magnetic disk during rotation of the magnetic disk by the action of an air flow produced in concert with the rotation of the magnetic disk.
However, if the surface roughness of the magnetic disk in the CSS type magnetic disk drive is reduces, the contact area between the flying surface (air bearing surface) of the magnetic head slider and the surface of the magnetic disk upon stoppage of rotation of the magnetic disk becomes large. Accordingly, there is a possibility of stiction between the magnetic head slider and the magnetic disk at the starting rotation of the magnetic disk. As a measure against this stiction problem, it has been proposed to apply texture forming by laser to a CSS zone of the magnetic disk or provide a plurality of pads (projections) on the flying surface (air bearing surface) of the head slider in the CSS type magnetic disk drive.
A portable personal computer such as a notebook personal computer is often carried, and it is therefore required to have high shock resistance. Accordingly, such a personal computer generally employs a load/unload type magnetic disk drive designed so that a head slider is unloaded from the surface of a magnetic disk when the computer is powered off or put into a sleep mode and that the head slider is loaded to the surface of the magnetic disk when the computer is operated. That is, when the computer is powered off or put into a sleep mode, a horn portion formed at the front end of a suspension is seated on a ramp (inclined portion) of a ramp member provided near the outer circumference of the magnetic disk to retract the head slider flying a microscopic height above the disk surface from the magnetic disk. Accordingly, even when the computer receives shock, it is possible to avoid the possibility that the head slider may collide with the magnetic disk to damage the magnetic disk.
Such a magnetic disk drive having a load/unload mechanism is required to have a highly reliable magnetic head slider that is prevented from coming into contact or collision with a magnetic disk not only while the head slider is flying above the disk, but also when the head slider is loaded to the disk.
A negative pressure type magnetic head slider is widely used in recent magnetic disk drives, so as to reduce the flying height of the magnetic head slider from the magnetic disk. A conventional negative pressure type magnetic head slider is mounted on a suspension so that the flying surface of the head slider becomes parallel to the magnetic disk at the instant when the head slider is loaded from the ramp member to the magnetic disk. Accordingly, there is a possibility that the head slider may come into contact with the disk because of a negative pressure generated on the head slider at the instant of loading.
Particularly in the case that a groove for generating a negative pressure is formed on the flying surface of the head slider so as to extend from a position upstream of the longitudinal center of the head slider to an air outlet end of the head slider, the head slider is inclined so that an air inlet end of the head slider is drawn to the magnetic disk by the negative pressure at the instant of loading, causing the contact of the air inlet end with the magnetic disk. Further, in the case that the head slider is mounted on a suspension having a pivot for supporting the head slider by applying a push load, the head slider is supported at its longitudinal center by the pivot.
Accordingly, in the case that the above-mentioned groove for generating a negative pressure is formed on the head slider, the attitude of the head slider cannot be controlled by the push load. As a result, the head slider is inclined so that the air inlet end is drawn to the magnetic disk by the negative pressure at the instant of loading, causing the contact of the air inlet end with the magnetic disk. Further, in the case that the head slider has a taper near the air inlet end or a pad having a raised surface and a step surface lower in level than the raised surface for generating a positive pressure near the air inlet end, and that the above-mentioned groove for generating a negative pressure is formed on the head slider, there is a possibility that the negative pressure may become greater than the positive pressure, depending upon the mounted attitude of the head slider. Accordingly, the head slider is inclined so that the air inlet end is drawn to the magnetic disk by the negative pressure at the instant of loading, causing the contact of the air inlet end with the magnetic disk.
It is therefore an object of the present invention to provide a negative pressure type magnetic head slider for use in a magnetic disk drive having a load/unload mechanism which can reliably prevent the contact of the head slider with a magnetic disk at the time of loading.
It is another object of the present invention to provide a magnetic disk drive having a load/unload mechanism which can reliably prevent the contact of a magnetic head slider with a magnetic disk at the time of loading.
In accordance with an aspect of the present invention, there is provided a disk drive comprising a housing having a base; a disk rotatably mounted in the housing and having a plurality of tracks; a negative pressure type head slider having a transducer for reading/writing data from/to the disk, an air inlet end, and an air outlet end; an actuator for moving the head slider across the tracks of the disk; means for controlling the actuator to load/unload the head slider with respect to the disk; and a ramp member fixed to the base for supporting the head slider unloaded; the actuator comprising an actuator arm rotatably mounted to the base; and a head assembly mounted on a front end portion of the actuator arm; the head assembly comprising a suspension; a gimbal formed integrally with the suspension and having a slider mounting portion; the head slider mounted on the slider mounting portion of the gimbal; and a supporting plate fixed to the suspension and having a pivot kept in contact with the slider mounting portion of the gimbal to support the head slider; the pivot supporting the head slider at a position shifted from the longitudinal center of the head slider toward the air outlet end by a distance less than 20% of the length of the head slider.
Preferably, the pivot supports the head slider at a position shifted from the longitudinal center of the head slider toward the air outlet end by a distance falling in the range of about 4% to about 15% of the length of the head slider.
In accordance with another aspect of the present invention, there is provided a disk drive comprising a housing having a base; a disk rotatably mounted in the housing and having a plurality of tracks; a negative pressure type head slider having a transducer for reading/writing data from/to the disk, an air inlet end, an air outlet end, and a disk opposing surface; an actuator for moving the head slider across the tracks of the disk; means for controlling the actuator to load/unload the head slider with respect to the disk; and a ramp member fixed to the base for supporting the head slider unloaded; the actuator comprising an actuator arm rotatably mounted to the base; and a head assembly mounted on a front end portion of the actuator arm; the head assembly comprising a suspension; a gimbal formed integrally with the suspension and having a slider mounting portion and a neck portion for connecting the slider mounting portion and the suspension; and the head slider mounted on the slider mounting portion of the gimbal; the neck portion being bent in such a direction that the disk opposing surface of the head slider is inclined with respect to the disk so as to raise the air inlet end in order that a given pitch angle is given to the head slider when the head slider is separated from the ramp member and loaded above the disk.
In accordance with a further aspect of the present invention, there is provided a disk drive comprising a housing having a base; a disk rotatably mounted in the housing and having a plurality of tracks; a negative pressure type head slider having a transducer for reading/writing data from/to the disk, an air inlet end, an air outlet end, and a disk opposing surface; an actuator for moving the head slider across the tracks of the disk; means for controlling the actuator to load/unload the head slider with respect to the disk; and a ramp member fixed to the base for supporting the head slider unloaded; the actuator comprising an actuator arm rotatably mounted to the base; a suspension having a base end portion fixed to a front end portion of the actuator arm; and the head slider mounted on a front end portion of the suspension; the head slider comprising a pair of rails formed on the disk opposing surface, each of the rails having a flat air bearing surface for generating a flying force during rotation of the disk; a groove defined between the rails for generating a negative pressure by expanding air once compressed near the air inlet end; a first taper formed at an end portion of each rail near the air inlet end so as to continue to the air bearing surface, the first taper having a first taper angle; and a second taper formed at the end portion of each rail so as to continue to the first taper, the second taper having a second taper angle larger than the first taper angle.
Preferably, the first taper angle is in the range of 0.1xc2x0 to 3xc2x0, and the second taper angle is not greater than 6xc2x0.
In accordance with a still further aspect of the present invention, there is provided a disk drive comprising a housing having a base; a disk rotatably mounted in the housing and having a plurality of tracks; a negative pressure type head slider having a transducer for reading/writing data from/to the disk, an air inlet end, an air outlet end, and a disk opposing surface; an actuator for moving the head slider across the tracks of the disk; means for controlling the actuator to load/unload the head slider with respect to the disk; and a ramp member fixed to the base for supporting the head slider unloaded; the actuator comprising an actuator arm rotatably-mounted to the base; a suspension having a base end portion fixed to a front end portion of the actuator arm; and the head slider mounted on a front end portion of the suspension; the head slider comprising a front pad formed on the disk opposing surface near the air inlet end, the front pad having a raised surface and a step surface lower in level than the raised surface; a groove for generating a negative pressure by expanding air once compressed by the front pad; and a taper formed adjacent to the air inlet end so as to continue to the step surface, the taper having a given taper angle.
Preferably, the given taper angle is in the range of 0.1xc2x0 to 6xc2x0.
In accordance with a still further aspect of the present invention, there is provided a disk drive comprising a housing having a base; a disk rotatably mounted in the housing and having a plurality of tracks; a negative pressure type head slider having a transducer for reading/writing data from/to the disk, an air inlet end, an air outlet end, and a disk opposing surface; an actuator for moving the head slider across the tracks of the disk; means for controlling the actuator to load/unload the head slider with respect to the disk; and a ramp member fixed to the base for supporting the head slider unloaded; the actuator comprising an actuator arm rotatably mounted to the base; a suspension having a base end portion fixed to a front end portion of the actuator arm; and the head slider mounted on a front end portion of the suspension; the head slider comprising a front pad formed on the disk opposing surface near the air inlet end, the front pad having a raised surface, a first step surface lower in level than the raised surface, and a second step surface lower in level than the first step surface; and a groove for generating a negative pressure by expanding air once compressed by the front pad.
Preferably, the length of the second step surface in the longitudinal direction of the head slider is in the range of 10 xcexcm to 100 xcexcm.
The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description and appended claims with reference to the attached drawings showing some preferred embodiments of the invention.